The home side had the chance to move ahead midway through the first-half when Scott Wiseman was penalised for a challenge on Henderson.

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Boss Hill praises Barnsley spirit

But Henderson failed to capitalise, thumping the spot-kick over the crossbar.

Dawson tapped in his third of the season for Keith Hill's team after Millwall goalkeeper David Forde saved Jim O'Brien's shot.

Millwall faced an even tougher task when referee Trevor Kettle showed Smith a straight red for a lunge at David Perkins.

Wood pulled Kenny Jackett's side level when he collected Dany N'Guessan's ball over the top and guided a shot past Luke Steele.

But Tudgay thumped in the third goal of his loan spell from Nottingham Forest to inflict a second defeat in 17 games on Millwall.

Millwall manager Kenny Jackett: "Looking at the key points in the game we've missed a penalty, the sending off was a harsh one which we will be appealing, and the winning goal looked close to being offside.

"Going down to 10 galvanised us and we played better so it's hugely disappointing to lose.

"We were going all out for the win and it showed at the end. The penalty miss wasn't the only turning point in the game but it did have an effect on its outcome."

Barnsley manager Keith Hill: "I'm delighted with the performance and delighted with the effort but let's not get carried away.

"We must take it into the next game. We've been working hard all week on what we wanted to do. We had to give Millwall respect as they've been in excellent form and it worked for us."

Hill felt Smith's red card was harsh on the hosts, adding: "I don't think it was a sending-off, and at best it was a yellow.

Stephen Foster fouled by Chris Wood, the ref awards a free kick. Scott Wiseman restarts play with the free kick. Free kick awarded for a foul by Bobby Hassell on Liam Trotter. Free kick taken by James Henry.

53:55 Dismissal

Dismissal Adam Smith shown a red card.

52:15

The assistant referee flags for offside against Chris Dagnall. David Forde takes the indirect free kick.

51:50

Inswinging corner taken right-footed by Jim O'Brien from the left by-line, save made by David Forde.

51:30

Bobby Hassell takes a shot. Josh Wright gets a block in.

50:55

Liam Trotter concedes a free kick for a foul on Stephen Dawson. Direct free kick taken by Jim O'Brien.

50:12

Unfair challenge on Marcus Tudgay by Mark Beevers results in a free kick. Free kick taken by Stephen Foster.

49:56

The ball is swung over by Liam Feeney, clearance by Stephen Foster.

46:57

The official flags Chris Wood offside. Luke Steele restarts play with the free kick.

46:29

Liam Trotter gives away a free kick for an unfair challenge on Stephen Dawson. Free kick taken by Bobby Hassell.

45:16

James Henry crosses the ball, clearance by Stephen Foster.

45:01

The referee blows his whistle to start the second half.

45:00 +3:23 Half time

Half Time The referee blows for half time.

45:00 +2:58

John Stones takes a shot. Save made by David Forde.

45:00 +2:01

Shane Lowry takes a shot. Save by Luke Steele.

45:00 +0:47

Effort from inside the area by Jim O'Brien misses to the left of the goal.

45:00 +0:27

Shane Lowry concedes a free kick for a foul on Scott Golbourne. John Stones restarts play with the free kick.

44:32

The ball is crossed by James Henry.

44:17

Stephen Foster is flagged offside by the assistant referee. David Forde takes the free kick.

43:28

Free kick awarded for a foul by Liam Trotter on Chris Dagnall. Jim O'Brien restarts play with the free kick.

43:00

The ball is crossed by James Henry.

42:28

Darius Henderson takes a shot. Luke Steele makes a save.

40:54

Unfair challenge on Liam Feeney by Stephen Dawson results in a free kick. James Henry takes the free kick.

40:01

Liam Trotter has an effort at goal from just outside the box which goes wide of the right-hand upright.

39:24

Strike on goal comes in from James Henry from the free kick, Chris Dagnall gets a block in.